1. Field
This disclosure relates to a light exposure device. For example, this disclosure relates to a maskless exposure device.
2. Description of the Related Technology
Photoresists and exposure masks are usually used in patterning thin films on a semiconductor device or a flat panel display. For example, a thin film is deposited on a substrate and a photoresist film is coated thereon. The photoresist film is exposed to light through an exposure mask and developed to form a photoresist pattern. The thin film is then etched by using the photoresist pattern to form a thin film pattern.
Since the cost for manufacturing a panel for a semiconductor device or a flat panel display is lowered as the size of the panel increase, it is a recent trend to enlarge the panel. However, the increase of the panel size may cause the increase of the size of the exposure mask, thereby increasing the cost for the exposure mask.
In addition, it may be difficult to form minute thin film patterns, for example, having a width equal to or smaller than about 1.5 μm by using the exposure mask.
Alternatively, a maskless light exposure may be used for patterning thin films on a semiconductor device or a flat panel display. A maskless exposure device illuminates an exposure beam directly on a photoresist film without a mask to form a photoresist pattern. Examples of maskless exposure technologies may include a digital micro-mirror device (“DMD”) and a grating light valve (“GLV”).
DMD may have a slow exposure speed and may not be adapted to a minute pattern with a width equal to or smaller than about 2 μm.
GLV may have a relatively large deviation in a direction perpendicular to a scanning direction of an exposure beam compared with a deviation in the scanning direction when forming a pattern with a width equal to or smaller than about 1.5 μm. Furthermore, a ribbon used in GLV may easily deteriorate.